Lubricator for pneumatically operated tools



Oct. 28, 1958 LUBRICATOR FOR PNEUMATICALLY OPERATED TOOLS J. J. SHADA Filed Oct. 17, 1955 INVENTOR. JOSEPH J. .SHADA A T Iron/v5) United States Patent LUBRICATOR FOR PNEUMATICALLY OPERATED TOOLS Joseph J. Shada, Grand Rapids, Mich., assignor to Nu J ett Products Corporation, Grand Rapids, Mich., a corporation of Michigan Application October 17, 1955, Serial No. 540,691 8 Claims. Cl. 184-55 of lubricant introduced into the air stream. Another disadvantage has been the necessity for restricting the diameter of the air passageway near the wick in order to reduce the pressure at the top of the wick. These lubricators have also been lacking in any suitable means for regulating the pressure in the vicinity of the top of the wick except by varying the position of the wick itself. The object of this lubricator is to eliminate these'deficiencies. A

The primary object of this invention is to provide a lubricat'or having a positive means to adjust the quantity of oil introduced into the air stream. p Another object of this invention is to provide an exterior adjustment means for adjusting the quantity of lubricant introducedinto the air flowing through the air passageway for a pneumatic tool.

Still another object of this invention is to provide a means for adjusting the extent of the wick in the air passageway and at the same time adjusting the pressure near the top ofthe wick in order to regulate the quantity of lubricant introduced intothe air stream.

A further object of this invention is to provide an exterior means for adjusting the length of the wick exposed to the tools air stream. p

Another object is to provide an exterior means for adjusting the pressure in the air stream near the top of the wick.

These and other objects and purposes of this invention will be readily seen by one acquainted with the design andconstruction of pneumatic tools upon reading the following specification in conjunction with the accompanying drawings wherein:

Fig. 1 is an exploded oblique view of the lubricator.

Fig. 2 is a central sectional elevational view of the lubricator.

Fig. 3 is a fragmentary, side elevational view of the top portion of the lubricator.

Briefly, this invention is concerned with a lubricator for pneumatic tools wherein the lubricant is introduced into the air supply stream in a form of a fine spray of mist. The lubricator of this invention includes a lubricant chamber which communicates with the lower end of a wick. The top end of the wick extends into the air passageway for the pneumatic tool. The wick is biased in one direction and a stop member is provided for adjusting the length of the wick projecting intothe air 2,857,983 Patented Oct. 28, 1958 passageway. This is preferably accomplished by biasing the wick upwardly into the air passageway and providing an adjustable stop member extending downwardly and contacting the top end of the wick. Regulating the position of the stop member adjusts the extent of the wick into the air passageway. Preferably, the stop memher is shaped so that it provides a means for causing the air flowing past it to have a greater velocity so as to create a lower pressure in the immediate vicinity of the top of the wick. This eliminates the need for providing a restricted air passageway near the wick. More specifically this invention includes a tube extending downwardly into the lubricant chamber. The Wick is mounted for axial adjustment in the tube and a ring seal is provided between the interior of the tube and the wick. This ring seal normally prevents the lubricant from passing around the wick except when the wick is plugged up in which case the lubricant is allowed to flow past the seal and into the air stream.

In describing this invention the words upper, lower, top and bottom are used. The terms upper and top shall be taken to mean. toward the top of the apparatus as shown in Figs. 1 or 2. By the same token, lower and bottom means toward the bottom of the apparatus. The extent of the wick in the passageway means the amount extending or projecting into such passageway.

Referring specifically to the drawings, Figs. 1 and 2 show the lubricator having a lubricant chamber or reservoir 1 (Fig. 2) formed by the head 10, the cylindrical bowl 20, and the base 50. The head or. cover 10 has a circular recess 17 in its bottom surface in which the '0-ring 18 is nested. The base 50 has a similar shaped recess 52 in which the O-ring 53 is nested. The tubular bowl 20 fits into the recesses 17 and 52 and bears against the O-rings. The bowl 20 is held in place by the tube 30 secured to the head 10 and the base 50; When secured firmly against the head 10 and the base 50 the bowl 20 is sealed thereto permitting the lubricant chamber 1 to retain a lubricant without leaking.

Extending horizontally through the head or .cover 10 is an air passageway 11. The passageway 11 is threaded on both ends to receive fittings which are part of the supply line for the tool with which the lub ricator is used.

Extending vertically and axially through the center of the head 10 are the aligned lower bore 12 and upper bore 13, both of which extend to and thus communicate. with the air passageway 11.. The upper bore 13 is threaded at the top portion and has a reduced diameter at its lower portion 14. The lower bore 12 is threaded at its lower portion and has a reduced diameter at its upper portion. The head 10 also has a lubricant filler opening 15 which is threaded at the top to receive the cap 70. A breather port 16 (Fig. 1) extends from the bottom of the head (not shown) to the filler opening 15. An aperture 19 is provided between the passageway 11 and the lubricant chamber 1. This aperture communicates with the air passageway 11 at a stop remote from the wick 40. Thus, it creates a greater pressure in the chamber 1 than is normally present in the vicinity of the wick 40 which extends into the air passageway 11.

The tubular bowl 20 is fabricated from some type of plastic material or any other transparent material which will permit a visual indication of the quantity of lubricant in chamber 1. The bowl must be sufliciently rigid to withstand the forces necessary to seal the joints between the bowl and the base 50 and head 10.

The tube 30 has an upper threaded end 31 and a lower threaded end 32. The top end is adapted to be secured in the bore 12 and the lower end in hole 51. Thus, the interior of the tube 30 communicates with the air passageway 11. Located in the tube 30 is the wick 40 which extends through the tube upwardly into the air passageway 11. It is biased upwardly into the air passageway 11 by the spring 42 which is seated in the hole 51. The wick may be fabricated of any suitable material so long as it will provide capillary action for the lubricant and at the same time is sufliciently rigid and hard to withstand the abrasive action of the air stream. Suitable wick materials include sintered' glass or metal. Fibrous type wicks in some cases may work satisfactorily.

The tube 30 has an opening 33 permitting the lubricant to flow into the interior of the tube. The lubricant is prevented from passing around the wick 40 by the O- shaped sealing ring 41. The ring 41 has a circular cross section and is preferably made of rubber or any other type of resilient material. This ring serves to center the wick in the tube 30 while at the same time normally preventing the oil from passing around the ring to the air passageway 11. The exact function of the ring will be described in more detail in Operation.

Threadedly secured in the bore 13 of the head is an adjustable stop element 60. The element 60 includes a knob 61 attached to a stem 62. Located intermediate the stem is theenlarged threaded portion 63 which en- 7 gages the threads of the bore 13 and provides the means for axially adjusting the element 60. At the lower end of the stem 62 there is attached or made integral therewith a cone shaped member 65 which is adapted to contact the top end of the wick 40. The exact function of the cone shaped member 65 will be described in more detail in Operation.

The cap 70 having the knob 71 and the threaded end 72 is adapted to be screwed into the filler hole to prevent lubricant from splashing or spilling out of chamber 1.

Assembling Of the lubricator The assembling of the lubricator is verysimple. The tube '30 is first threaded into the threaded hole 51 of the base 50; Then the spring 42 is dropped into the hole through the tube 30 and the wick with the ring seal 41 thereon is inserted into the tube 30. The cylindrical bowl is then placed in the recess 52 directly on the O-ri-ng 53. The top threaded end 31 of the tube is then threaded into the bore 12 until a tight joint is established between the top of the bowl 20 and the ring 18 and the bottomedge of the bowl 20 and the O-ring 53. The adjustable stop member is then threaded into the upper bore 13 of the head 11. The lubricant is poured into thefiller hole 15 until the chamber 1 is substantially full. The cap 70 is then screwed into the opening 51 to prevent the lubricant from splashing or spilling out. The entire lubricator is then aflixed in the supply line of the pneumatic toolwith which the lubricator is to be used. The adjustable stop member is then adjusted to regulate the quantity of lubricant desired.

When the lubricator is entirely assembled, the opening 33 in the tube 30 is below the level of the lubricant. Thus the lubricant is permitted to pass into the inside of the tube and through the wick. Normally the ring seal 41 prevents the lubricant from passing about the wick. At

the top of the unit the ring seal 64 on the adjustable stop ber 65 of the adjustable stop member 60 determines the position or the extent of the wick 42 into the air passageway 11. Air from the passageway 11 is admitted to the chamber 1 by the aperture 19 in the bottom of the head 10.

Operation The lubricator of this invention operates primarily by capillary action caused by the pressure differential between the vicinity of the top of the wick and the air space in chamber 1. The quantity of lubricant introduced into the air flowing through passageway 11 is determined by the diflerence in pressure at these two points and also I the extent of the wick in the passageway 11.

When the adjustable stop member is screwed entirely down, the bottom edge of the cone shaped member bears against the wall of the. passageway 11 closing the top entrance to the bore 12. In this position no lubricant is picked up by the air as it flows through. the passageway 1'1. Upon screwing the adjustable stop member upwardly, the spring 42 biases the wick 41 into the passageway 11. This permits the lubricant passing through opening 33 and rising to the top of the wick to be introduced into the air as it flows through the passageway 11.

The flow of the lubricant up the wick is caused by the difference between the pressure in the space surrounding the wick and the pressure on the top of the lubricant. The increase in the velocity of the air flowing by the cone shaped. member 65 and the wick itself is increased because of the restricted cross-sectional area through which the air flows. This creates a lower pressure in the immediate vicinity of the top of the wick. Since the air space above the lubricant is in communication with the air passageway 11 at a spot remotely located from the top of the wick, the pressure on the top of the lubricant in the chamber 1 is greater than the pressure at the wick. Thus the lubricant is forced up the wick and into the air stream.

Fig. 3 shows a side elevational viewof the air passageway. It illustrates the restricted portion of the passageway made possible by the adjustable stop member. This restriction in the passageway causes the air to flow at a greater velocity past the wick 40 resulting in a decrease in pressure. It should be obvious that upon adjusting the member 60 by turning the knob 61 the restriction and thus the velocity of the air passing through the passageway in the vicinity of the wick 40 can be varied.

-As a result, the quantity of oil evaporated into the air stream can be regulated by this means as well as by adjusting the amount of the wick exposed to the air stream.

The shape of the cone shaped member can be varied in accordance with the different requirements for pneumatic tools. The shape can be varied so that a greater restriction to the air flowing through the passageway 11 results when a small portion of the wick is exposed to the air. In such a case, a greater dilference in pressure will result and there will be a greater pull on the lubricant resulting in a greater quantity of lubricant per unit area of exposed wick passing into the air stream. On the other hand, it may be desirable to shape the member 65 in such a manner that the greatest velocity is obtained when the wick is fully extended into the air passageway. This could be accomplished by extending the member 65 over and around the side of the wick leaving enough room for the air to pass therethrough. In the form shown the cone-shaped member 65 is tapered to compensate for the porosity of the wick and thus maintain the velocity and pressure in the passageway constant regardless of its position. It should be obvious that many different configurations of the member 65 can be made depending upon the requirements and the conditions for which the lubricator is to be used. In its broader aspect this invention applies to any and all such configurations wherein the restricted portion of the aperture 11 is created by a member other than the wick extending into the passageway, thereby avoiding the necessity of reducing the diameter of a portion of the air passageway.

It will be seen that this arrangement not only provides an exterior means for adjusting the differential pressure but it also provides an exterior means for adjusting "the position 'of'the wick 40. Heretofore, a satisfactory solution has not been found for making such exterior adjustments. With this lubricator, the adjustment is very simple. In this respect it should be noted that several equivalent structures could be used. For example, the adjustable stop member; if it is not to serve as a means for adjusting the velocity of the air through the passage, could be located in the base and the spring could be located in the head. In such a case, the spring would bias the wick out of the air passageway and this biasing means would be opposed by the adjustable stop member located in the base 50. The biasing means in either arrangement could be located in diiferent positions.

It should be understood that the exact arrangement is not necessary for practicing the broadest aspect of this invention. For example, the bores 13 and 12 need not be aligned. Conceivably, an adjustable member could be adjustably inserted through the side of the head at a 90 angle, or any other angle, to the bore 12. Then the adjustable member would act as a cam to adjust the position of the wick. The arrangement shown, however, .is the preferred arrangement and works most satisfactorily. It has many advantages over other conceivable types of adjustment means which fall within the broadest aspect of this invention.

Ring seal 41 serves several important functions. It centers the wick in the center of the tube 30, thus permitting the lubricant to enter the wick from all sides and to pass evenly up to the top of the wick where it will be distributed evenly in the air stream. For this purpose any type spacer could be used. For example, a split ring serves the purpose very well. One difficulty experienced in the split ring is that in most type wicks the exterior diameter of the wick is very uneven, thus the seal between the ring and the wick is not as good. However, such type rings will work and serve the purpose of centering the wick in order to establish an even dis tribution of oil throughout the entire Wick.

The ring 41 also provides a seal against the wick and the interior wall of the tube. This is another advantage of the type sealing ring shown which has a circular cross section and is made of resilient material such as rubber. This type ring, when the wick is adjusted, usually does not slide within the tube but rolls on the wick thus normally maintaining the seal between the members at all times. This rolling action eliminates friction between the seal and the tube 30 and the seal and wick 40, thus permitting easier adjustment of the wick.

Although the ring does provide a seal under normal conditions, it has another advantage in allowing the lubricant to flow past it when the wick is plugged due to parafiin deposits or otherwise. When the wick becomes plugged the pressure is much greater above the lubricant than the pressure in the vicinity of the end of the wick. Thus, the lubricant will be pushed past the ring because of the resiliency of the ring and also the looseness of the fit. This result can be obtained with other type rings previously discussed. It should be noted, however, that the preferred ring shown works more efiectively in normally preventing the escape of liquid past the seal.

Having described my invention it should be under- :stood that several modifications can be made and other :embodiments constructed without departing from the scope of the invention. Several details have been described which are not a necessary part of this invention. The

scope and the spirit of this invention should only be in- Any limitations of details described herein I claim: 1. In a lubricator for pneumatically operated tools,

the combination comprising: a lubricant supply chamber;

a housing secured to said chamber; an air passageway in said housing; a firstjbore between said passageway and said chamber; a tube secured in said bore and extending into said chamber below the level of the lubricant; the interior of said tube communicating with said chamber; a wick adjustably mounted in said tube and extending into said passageway; biasing means urging said wick into said passageway; a second bore in said housing extending from the exterior thereof to said passageway; an exteriorly adjustable member mounted in said bore for opposing said biasing means whereby the extent of said wick in said passageway can be varied; and a movable sealing ring located between the interior wall of said tube and said wickjfacilitating the easy movement of said wick by said biasing means in said tube and permitting by-pass of lubricant when said wick is plugged.

2. The lubricator defined in claim 1 in which the sealing ring has a circular cross section.

3. In a lubricator for pneumatically operated tools, the combination comprising: a lubricant supply chamber; a housing secured to said chamber; an air passageway in said housing; a first bore between said passageway and said chamber; a tube secured in said bore and extending into said chamber below the level of the lubricant; the interior of said tube communicating with said chamber; a rigid wick adjustably mounted in said tube and extending into said passageway; biasing means urging said wick into said passageway; a second bore in said housing opposite to and aligned with said first bore; an exteriorly vaxially adjustable member in said bore for opposing said biasing means whereby the extent of said wick in said passageway can be varied; and a movable sealing ring located between the interior wall of said tube and said wick facilitating the easy movement of said wick by said biasing means in said tube and permitting by-pass of lubricant when said wick is plugged.

4. The lubricator defined in claim 3 in which the ing ring has a circular cross section.

5. In a lubricator for pneumatically operated tools, the combination comprising: a lubricant supply chamber; a housing secured to said chamber; an air passageway in said housing; a bore between said passageway and said chamber; a tube secured in said bore and extending into said chamber below the level of the lubricant; the interior of said tube communicating with said chamber; a rigid wick adjustably mounted in said tube and extending into said passageway; a sealing ring located between the interior wall of said tube and said wick and movable with said wick when adjusted, facilitating the easy movement of said wick in said tube and permitting by-pass of lubricant when said wick is plugged; and exteriorly adjustable means for regulating the extent of said wick in said passageway.

6. The lubricator defined in claim 5 in which the sealing ring has a circular cross section thereby being capable of rolling on said wick.

7. In a lubricator for pneumatically operated tools, the combination comprising: a lubricant supply chamber; a housing secured to said chamber; an air passageway in said housing; a first bore between said passageway and said chamber; a tube secured in said bore and extending into said chamber below the level of the lubricant; the interior of said tube communicating with said chamber; a rigid wick adjustably mounted in said tube and extending into said passageway; a second bore in said housing opposite to and aligned with said first bore; and a coneshaped member axially adjustable in said. second bore and engaging said wick for adjusting the extent of said wick in said passageway; said cone-shaped member being tapered in a direction away from the top end of said wick to compensate for the porosity of the wick so that velocity of the air passing through said passageway is maintained substantially constant.

8. In a lubricator for pneumatically operated tools, the combination comprising: a lubricant supply chamber; a housing secured to said chamber; an air passageway in sealsaid housing; a first bore between said passageway and said chamber; a tube secured in said bore and extending into said chamber below the level of the lubricant; the interior of said tube c'ommunicating withsaid chamber; a rigid wick adjustably mounted in said tube and extending'into said passageway; biasing means urging said wick into said passageway; a second bore in saidhousing extending from the exterior thereof to said passageway; a cone-shaped meniber axially adjustable in said second bore and engaging said wick for adjusting the extent of said wick in said jiass'a'gewayg said cone-shaped member being tapered in a direction away from the top end of 'said wick to compensate for the porosity of the wick so that velocity of'the air passingthrough said passageway ismaintained substantially. constant; and a movable sealing ring located between the interior wall of said tube and said wick.

41,174 Bollinger Jan. 5, 1864 1,504,341 Hansen Aug. 12, 1924 2,439,910 Snyder Apr. 20, 1948 2,680,496 Johnson June 8, 1954 2,735,512 Faust Feb. 21, 1956 Booth a Oct. 2-3, 1956 

